The present invention relates to a pin plug comprising an inner contact member in the form of a pin made of electrically conductive metal, an outer contact member in the form of a hollow cylindrical body made of electrically conductive material and an electrically insulating member for fixing said inner and outer contact members in position in an electrically isolated manner, whereby one of two conductors of an electric wire is connected to said inner contact member and the other conductor is connected to the outer contact member.
Such pin plugs are used in various electronic and electric apparatuses. For example, an audio apparatus of a system componets type various conponents such as a radio tuner, a pre-amplifier, a main amplifier, a record disc player, a magnetic tape deck, a loudspeaker system are interconnected by means of electric wires having the pin plugs connected at their ends. In case of a stereophonic audio apparatus two electric wires each conducting right and left channel signals, respectively are usually bundled as a single wire code. Such a wire code has four pin plugs. Even if one of the four pin plugs is broken, the whole wire code could not be used, because the known pin plug is difficult to repair. Therefore a yield of such a pin plug wire is very small.
In one of the known pin plugs use is made of an electrically insulating plate and the inner and outer contact members are fixed in position by means of the insulating plate. Then the assembly is covered with an electrically insulating cover by molding. Such a pin plug cannot be manufactured in a simple manner and has a poor electrical property, particularly a poor insulating characteristic. In another known pin plug the inner and outer contact members are inserted at suitable positions in molds and are fixed in position by molded body of electrically insulating material. This pin plug has a relatively good electrical property, but its mechanical strength is not so large. Particularly such a pin plug has a drawback that its yield is relatively low. At any rate in the known pin plug since the pin plug could not be taken apart or disassembled after the outer mold of insulating material has been applied, when its electrical or mechanical property becomes deteriorated, the whole wire having the pin plugs attached at its ends cannot be used any longer.
The present invention has for its object to provide a pin plug which can be easily manufactured and taken apart in a simple manner, so that even if the pin plug has a poor insulating characteristic, a disconnection of conductors, etc., it can be easily repaired.
Another object of the present invention is to provide a pin plug which has excellent electrical and mechanical properties.
It is still another object of the invention to provide a pin plug which can be manufactured with a very high yield.